In order to improve the communication rate of the communication and ranging composite system, the parallel combinatory spread spectrum(PCSS) technology is applied to the composite system, and the Gold sequence with good correlation characteristics is used as the spread spectrum sequence. To realize the complete data mapping and increases the transmittable data bits, an improved r_combinatory data-sequence mapping method is proposed. The proposed mapping method is used to implement the data spreading transmission at the transmitter, and an improved generalized cross-correlation algorithm is adopted to estimate the transmission tine delay and data despreading at the receiver, then the information transmission and distance measuring can be implemented at the same time. The simulation results show that the improved PCSS communication and ranging composite system realizes the uniqueness of mapping, improves the data mapping efficiency and the information transmission ability of the system, the improved generalized cross-correlation algorithm has better delay estimation performance under low signal-to-noise ratio (SNR), which makes the system accomplish ranging tasks and communication tasks more effectively.